Accession Number:

ADA327240

Title:

Materials Development Research.

Descriptive Note:

Final rept. 28 Mar 92-30 Sep 96,

Corporate Author:

UNIVERSAL ENERGY SYSTEMS INC DAYTON OH

Report Date:

1996-11-01

Pagination or Media Count:

189.0

Abstract:

Research has been carried out in three materials areas Advanced Metallics two systems -- Gamma-TiAl alloys and NbTisilicide composites are being developed as high temperature structural materials. The research includes chemistryprocessingmicrostructureproperty relations to provide a specific balance of mechanical properties. A physical vapor deposition system has been built to produce nanolayered and nanocrystalline materials. Quantitative models have been developed to describe the yield strength of gamma-TiAl alloys, metallic multilayers and nanocrystalline Al alloys. Theoretical work has been carried out, using a variety of analytical and computational tools, to predict fundamental aspects of plasticity and fracture on length scales connected to electronic, atomistic and continuum levels. Advanced Metallic Compositions research has involved SiC fiberTi matrix composites with focus on interface and matrix chemistrymicrostructures to provide optimum mechanical properties. The interfaces were studied by testing composites containing only a few fibers while the matrix development involved chemistry and heat treatment optimization. Ceramic Matrix Composites work included studies on experimental mechanics, fiber coatings and oxide-oxide composites. Models were developed to study the effect of matrix roughness on fiber push outpull out. Various fibermatrix interface control concepts to weaken interfaces by oxidation resistant means were explored. Fugitive interface concept was successfully demonstrated on oxide-oxide composites.

Subject Categories:

  • Laminates and Composite Materials
  • Mechanics
  • Coatings, Colorants and Finishes

Distribution Statement:

APPROVED FOR PUBLIC RELEASE